Let's compare the various ENY:
EW: IIC=10 which is equal to the Spit V
It's higher than the Spit IX, P38G, and 190A5
It's 1/2 the ENY of a Zeke
MW: IIC=15 which is equal to the F6F, P38J and Seafire
It's higher than the Spit VIII, Typhoon, Bf110G2, LA5 and P51B
It's lower than the Spit V and IX, Yak9 and Zeke
LW: IIC=10 which is equal to the Bf110G2, Sp VIII and Typhoon
It's greater than the F4U-1C, F4U-4, LA7, Niki, P47N, Spit XIV/XVI, Tempest, and P51D
It's lower than the Ki84, Zeke, all 109's and Spit IX
I'd say that overall the ENY's aren't unreasonable but there could be some fine tuning. A Bf-110G2 doesn't stand a chance except in a HO and I don't understand it going from a lower ENY in MW to an equal ENY in LW, it should be higher in all the arenas. The Zeke is the only one that can realistically out turn the IIC and it's faster so I'd say the Zeke, purely from a threat perspective, should have a lower ENY. It probably doesn't since it's pretty fragile. All the Spits I listed have 20mm plus speed and maneuverability, don't really see a big difference when it comes to fighting the Hurri with any of them except a Spit I. Don't know why the Typhoon goes from lower ENY in MW to equal in LW. Every other plane listed has both a speed and climb advantage if I remember all the numbers. This, in the majority of cases allows them to chose a fight, unlike the Hurri which usually has to take what he gets.
Overall, I'd say the IIC has three things going for it, the guns, the turn and it's toughness. I can't vouch for the Hurri's RL toughness, but's it's definently a tough old bird in AH. On the down side it has lousy e retention, B&Z in it is more of a B&zzzzz, and the great cannons are offset somewhat by the limited ammo. As has been mentioned it can't run away from anything except maybe an M8.
I agree that there are many more IIC's flying than in the old MA. I remember when a IIC was a very rare plane to come across which is one of the reasons I sort of latched onto it. It was ugly, slow and no one loved it but with some experience it's like sex with a 40 year-old divorcee, she'll do things that'll water your eyes and can be a cast iron b***h if you cross her.
With the new areans, predominently the EW, there do appear to be quite a number of guys who don't know how to get the lovin' out of her and seem to up it just for the HOs. Given the performance and cannons of the airplanes in EW with a lower ENY I don't see the beef other than it'll take some time for people to really learn the plane for anything except a HO but then that's not much different than the 110, 190 and Mossie. It seems to me that I see far more HO attempts by 190's than by IICs but that's just my impression, I've never counted so could be wrong. I can't tell you how often I've been jumped as a single by four or five 190's, 109s, P51s, etc., only to be accused of HOing as I twist and turn on the deck avoiding their B&Z. Under those conditions (quite common in such a slow plane) I'll shoot anyone that gets near my nose, if it ends up being a HO then so be it. Most of my kills actually come from deflections, snapshots, or dead six. Those guys that don't understand what an overshoot is are usually the ones on the receiving end.
Regarding the K/D ratios, it's my experience that the Spits and Pony's (and other "better" planes) die because they don't use good tactics and tend to be overconfident in their abilities. Many of the high/fast flyers get impatient or don't have a real plan against the Hurri, they think they'll just dive in on the slow/low plane, make one pass and then run off and land their kill. That's kinda foolish. Smart tactics, especially when a guy works an altitude/e advantage, are very tough for a Hurri to beat since, as I said before, almost every plane has a speed and climb advantage over it. IMO, the ENY should be based, as well as it can be, on the technical superiority of the aircraft, not on foolish tactics and the ENY appears fairly reasonable.